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/*
 * lib/route/route_obj.c        Route Object
 *
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation version 2.1
 *      of the License.
 *
 * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
 */

/**
 * @ingroup route
 * @defgroup route_obj Route Object
 *
 * @par Attributes
 * @code
 * Name                                           Default
 * -------------------------------------------------------------
 * routing table                                  RT_TABLE_MAIN
 * scope                                          RT_SCOPE_NOWHERE
 * tos                                            0
 * protocol                                       RTPROT_STATIC
 * prio                                           0
 * family                                         AF_UNSPEC
 * type                                           RTN_UNICAST
 * iif                                            NULL
 * @endcode
 *
 * @{
 */

#include <netlink-local.h>
#include <netlink/netlink.h>
#include <netlink/cache.h>
#include <netlink/utils.h>
#include <netlink/data.h>
#include <netlink/route/rtnl.h>
#include <netlink/route/route.h>
#include <netlink/route/link.h>
#include <netlink/route/nexthop.h>

/** @cond SKIP */
#define ROUTE_ATTR_FAMILY    0x000001
#define ROUTE_ATTR_TOS       0x000002
#define ROUTE_ATTR_TABLE     0x000004
#define ROUTE_ATTR_PROTOCOL  0x000008
#define ROUTE_ATTR_SCOPE     0x000010
#define ROUTE_ATTR_TYPE      0x000020
#define ROUTE_ATTR_FLAGS     0x000040
#define ROUTE_ATTR_DST       0x000080
#define ROUTE_ATTR_SRC       0x000100
#define ROUTE_ATTR_IIF       0x000200
#define ROUTE_ATTR_OIF       0x000400
#define ROUTE_ATTR_GATEWAY   0x000800
#define ROUTE_ATTR_PRIO      0x001000
#define ROUTE_ATTR_PREF_SRC  0x002000
#define ROUTE_ATTR_METRICS   0x004000
#define ROUTE_ATTR_MULTIPATH 0x008000
#define ROUTE_ATTR_REALMS    0x010000
#define ROUTE_ATTR_CACHEINFO 0x020000
/** @endcond */

static void route_constructor(struct nl_object *c)
{
        struct rtnl_route *r = (struct rtnl_route *) c;

        r->rt_family = AF_UNSPEC;
        r->rt_scope = RT_SCOPE_NOWHERE;
        r->rt_table = RT_TABLE_MAIN;
        r->rt_protocol = RTPROT_STATIC;
        r->rt_type = RTN_UNICAST;

        nl_init_list_head(&r->rt_nexthops);
}

static void route_free_data(struct nl_object *c)
{
        struct rtnl_route *r = (struct rtnl_route *) c;
        struct rtnl_nexthop *nh, *tmp;

        if (r == NULL)
                return;

        nl_addr_put(r->rt_dst);
        nl_addr_put(r->rt_src);
        nl_addr_put(r->rt_pref_src);

        nl_list_for_each_entry_safe(nh, tmp, &r->rt_nexthops, rtnh_list) {
                rtnl_route_remove_nexthop(r, nh);
                rtnl_route_nh_free(nh);
        }
}

static int route_clone(struct nl_object *_dst, struct nl_object *_src)
{
        struct rtnl_route *dst = (struct rtnl_route *) _dst;
        struct rtnl_route *src = (struct rtnl_route *) _src;
        struct rtnl_nexthop *nh, *new;

        if (src->rt_dst)
                if (!(dst->rt_dst = nl_addr_clone(src->rt_dst)))
                        return -NLE_NOMEM;

        if (src->rt_src)
                if (!(dst->rt_src = nl_addr_clone(src->rt_src)))
                        return -NLE_NOMEM;

        if (src->rt_pref_src)
                if (!(dst->rt_pref_src = nl_addr_clone(src->rt_pref_src)))
                        return -NLE_NOMEM;

        nl_init_list_head(&dst->rt_nexthops);
        nl_list_for_each_entry(nh, &src->rt_nexthops, rtnh_list) {
                new = rtnl_route_nh_clone(nh);
                if (!new)
                        return -NLE_NOMEM;

                rtnl_route_add_nexthop(dst, new);
        }

        return 0;
}

static void route_dump_line(struct nl_object *a, struct nl_dump_params *p)
{
        struct rtnl_route *r = (struct rtnl_route *) a;
        struct nl_cache *link_cache;
        int cache = 0, flags;
        char buf[64];

        link_cache = nl_cache_mngt_require("route/link");

        if (r->rt_flags & RTM_F_CLONED)
                cache = 1;

        nl_dump_line(p, "%s ", nl_af2str(r->rt_family, buf, sizeof(buf)));

        if (cache)
                nl_dump(p, "cache ");

        if (!(r->ce_mask & ROUTE_ATTR_DST) ||
            nl_addr_get_len(r->rt_dst) == 0)
                nl_dump(p, "default ");
        else
                nl_dump(p, "%s ", nl_addr2str(r->rt_dst, buf, sizeof(buf)));

        if (r->ce_mask & ROUTE_ATTR_TABLE && !cache)
                nl_dump(p, "table %s ",
                        rtnl_route_table2str(r->rt_table, buf, sizeof(buf)));

        if (r->ce_mask & ROUTE_ATTR_TYPE)
                nl_dump(p, "type %s ",
                        nl_rtntype2str(r->rt_type, buf, sizeof(buf)));

        if (r->ce_mask & ROUTE_ATTR_TOS && r->rt_tos != 0)
                nl_dump(p, "tos %#x ", r->rt_tos);

        if (r->ce_mask & ROUTE_ATTR_MULTIPATH) {
                struct rtnl_nexthop *nh;

                nl_list_for_each_entry(nh, &r->rt_nexthops, rtnh_list) {
                        p->dp_ivar = NH_DUMP_FROM_ONELINE;
                        rtnl_route_nh_dump(nh, p);
                }
        }

        flags = r->rt_flags & ~(RTM_F_CLONED);
        if (r->ce_mask & ROUTE_ATTR_FLAGS && flags) {

                nl_dump(p, "<");

#define PRINT_FLAG(f) if (flags & RTNH_F_##f) { \
                flags &= ~RTNH_F_##f; nl_dump(p, #f "%s", flags ? "," : ""); }
                PRINT_FLAG(DEAD);
                PRINT_FLAG(ONLINK);
                PRINT_FLAG(PERVASIVE);
#undef PRINT_FLAG

#define PRINT_FLAG(f) if (flags & RTM_F_##f) { \
                flags &= ~RTM_F_##f; nl_dump(p, #f "%s", flags ? "," : ""); }
                PRINT_FLAG(NOTIFY);
                PRINT_FLAG(EQUALIZE);
                PRINT_FLAG(PREFIX);
#undef PRINT_FLAG

#define PRINT_FLAG(f) if (flags & RTCF_##f) { \
                flags &= ~RTCF_##f; nl_dump(p, #f "%s", flags ? "," : ""); }
                PRINT_FLAG(NOTIFY);
                PRINT_FLAG(REDIRECTED);
                PRINT_FLAG(DOREDIRECT);
                PRINT_FLAG(DIRECTSRC);
                PRINT_FLAG(DNAT);
                PRINT_FLAG(BROADCAST);
                PRINT_FLAG(MULTICAST);
                PRINT_FLAG(LOCAL);
#undef PRINT_FLAG

                nl_dump(p, ">");
        }

        nl_dump(p, "\n");
}

static void route_dump_details(struct nl_object *a, struct nl_dump_params *p)
{
        struct rtnl_route *r = (struct rtnl_route *) a;
        struct nl_cache *link_cache;
        char buf[128];
        int i;

        link_cache = nl_cache_mngt_require("route/link");

        route_dump_line(a, p);
        nl_dump_line(p, "    ");

        if (r->ce_mask & ROUTE_ATTR_PREF_SRC)
                nl_dump(p, "preferred-src %s ",
                        nl_addr2str(r->rt_pref_src, buf, sizeof(buf)));

        if (r->ce_mask & ROUTE_ATTR_SCOPE && r->rt_scope != RT_SCOPE_NOWHERE)
                nl_dump(p, "scope %s ",
                        rtnl_scope2str(r->rt_scope, buf, sizeof(buf)));

        if (r->ce_mask & ROUTE_ATTR_PRIO)
                nl_dump(p, "priority %#x ", r->rt_prio);

        if (r->ce_mask & ROUTE_ATTR_PROTOCOL)
                nl_dump(p, "protocol %s ",
                        rtnl_route_proto2str(r->rt_protocol, buf, sizeof(buf)));

        if (r->ce_mask & ROUTE_ATTR_IIF) {
                if (link_cache) {
                        nl_dump(p, "iif %s ",
                                rtnl_link_i2name(link_cache, r->rt_iif,
                                                 buf, sizeof(buf)));
                } else
                        nl_dump(p, "iif %d ", r->rt_iif);
        }

        if (r->ce_mask & ROUTE_ATTR_SRC)
                nl_dump(p, "src %s ", nl_addr2str(r->rt_src, buf, sizeof(buf)));

        nl_dump(p, "\n");

        if (r->ce_mask & ROUTE_ATTR_MULTIPATH) {
                struct rtnl_nexthop *nh;

                nl_list_for_each_entry(nh, &r->rt_nexthops, rtnh_list) {
                        nl_dump_line(p, "    ");
                        p->dp_ivar = NH_DUMP_FROM_DETAILS;
                        rtnl_route_nh_dump(nh, p);
                        nl_dump(p, "\n");
                }
        }

        if ((r->ce_mask & ROUTE_ATTR_CACHEINFO) && r->rt_cacheinfo.rtci_error) {
                nl_dump_line(p, "    cacheinfo error %d (%s)\n",
                        r->rt_cacheinfo.rtci_error,
                        strerror(-r->rt_cacheinfo.rtci_error));
        }

        if (r->ce_mask & ROUTE_ATTR_METRICS) {
                nl_dump_line(p, "    metrics [");
                for (i = 0; i < RTAX_MAX; i++)
                        if (r->rt_metrics_mask & (1 << i))
                                nl_dump(p, "%s %u ",
                                        rtnl_route_metric2str(i+1,
                                                              buf, sizeof(buf)),
                                        r->rt_metrics[i]);
                nl_dump(p, "]\n");
        }
}

static void route_dump_stats(struct nl_object *obj, struct nl_dump_params *p)
{
        struct rtnl_route *route = (struct rtnl_route *) obj;

        route_dump_details(obj, p);

        if (route->ce_mask & ROUTE_ATTR_CACHEINFO) {
                struct rtnl_rtcacheinfo *ci = &route->rt_cacheinfo;

                nl_dump_line(p, "    used %u refcnt %u last-use %us "
                                "expires %us\n",
                             ci->rtci_used, ci->rtci_clntref,
                             ci->rtci_last_use / nl_get_hz(),
                             ci->rtci_expires / nl_get_hz());
        }
}

static void route_dump_env(struct nl_object *obj, struct nl_dump_params *p)
{
        struct rtnl_route *route = (struct rtnl_route *) obj;
        struct nl_cache *link_cache;
        char buf[128];

        link_cache = nl_cache_mngt_require("route/link");

        nl_dump_line(p, "ROUTE_FAMILY=%s\n",
                     nl_af2str(route->rt_family, buf, sizeof(buf)));

        if (route->ce_mask & ROUTE_ATTR_DST)
                nl_dump_line(p, "ROUTE_DST=%s\n",
                             nl_addr2str(route->rt_dst, buf, sizeof(buf)));

        if (route->ce_mask & ROUTE_ATTR_SRC)
                nl_dump_line(p, "ROUTE_SRC=%s\n",
                             nl_addr2str(route->rt_src, buf, sizeof(buf)));

        if (route->ce_mask & ROUTE_ATTR_PREF_SRC)
                nl_dump_line(p, "ROUTE_PREFSRC=%s\n",
                             nl_addr2str(route->rt_pref_src, buf, sizeof(buf)));

        if (route->ce_mask & ROUTE_ATTR_IIF) {
                if (link_cache) {
                        nl_dump_line(p, "ROUTE_IIF=%s",
                                rtnl_link_i2name(link_cache, route->rt_iif,
                                                 buf, sizeof(buf)));
                } else
                        nl_dump_line(p, "ROUTE_IIF=%d", route->rt_iif);
        }

        if (route->ce_mask & ROUTE_ATTR_TOS)
                nl_dump_line(p, "ROUTE_TOS=%u\n", route->rt_tos);

        if (route->ce_mask & ROUTE_ATTR_TABLE)
                nl_dump_line(p, "ROUTE_TABLE=%u\n",
                             route->rt_table);

        if (route->ce_mask & ROUTE_ATTR_SCOPE)
                nl_dump_line(p, "ROUTE_SCOPE=%s\n",
                             rtnl_scope2str(route->rt_scope, buf, sizeof(buf)));

        if (route->ce_mask & ROUTE_ATTR_PRIO)
                nl_dump_line(p, "ROUTE_PRIORITY=%u\n",
                             route->rt_prio);

        if (route->ce_mask & ROUTE_ATTR_TYPE)
                nl_dump_line(p, "ROUTE_TYPE=%s\n",
                             nl_rtntype2str(route->rt_type, buf, sizeof(buf)));

        if (route->ce_mask & ROUTE_ATTR_MULTIPATH) {
                struct rtnl_nexthop *nh;
                int index = 1;

                if (route->rt_nr_nh > 0)
                        nl_dump_line(p, "ROUTE_NR_NH=%u\n", route->rt_nr_nh);

                nl_list_for_each_entry(nh, &route->rt_nexthops, rtnh_list) {
                        p->dp_ivar = index++;
                        rtnl_route_nh_dump(nh, p);
                }
        }
}

static int route_compare(struct nl_object *_a, struct nl_object *_b,
                        uint32_t attrs, int flags)
{
        struct rtnl_route *a = (struct rtnl_route *) _a;
        struct rtnl_route *b = (struct rtnl_route *) _b;
        struct rtnl_nexthop *nh_a, *nh_b;
        int i, diff = 0, found;

#define ROUTE_DIFF(ATTR, EXPR) ATTR_DIFF(attrs, ROUTE_ATTR_##ATTR, a, b, EXPR)

        diff |= ROUTE_DIFF(FAMILY,      a->rt_family != b->rt_family);
        diff |= ROUTE_DIFF(TOS,         a->rt_tos != b->rt_tos);
        diff |= ROUTE_DIFF(TABLE,       a->rt_table != b->rt_table);
        diff |= ROUTE_DIFF(PROTOCOL,    a->rt_protocol != b->rt_protocol);
        diff |= ROUTE_DIFF(SCOPE,       a->rt_scope != b->rt_scope);
        diff |= ROUTE_DIFF(TYPE,        a->rt_type != b->rt_type);
        diff |= ROUTE_DIFF(PRIO,        a->rt_prio != b->rt_prio);
        diff |= ROUTE_DIFF(DST,         nl_addr_cmp(a->rt_dst, b->rt_dst));
        diff |= ROUTE_DIFF(SRC,         nl_addr_cmp(a->rt_src, b->rt_src));
        diff |= ROUTE_DIFF(IIF,         a->rt_iif != b->rt_iif);
        diff |= ROUTE_DIFF(PREF_SRC,    nl_addr_cmp(a->rt_pref_src,
                                                    b->rt_pref_src));

        if (flags & LOOSE_COMPARISON) {
                nl_list_for_each_entry(nh_b, &b->rt_nexthops, rtnh_list) {
                        found = 0;
                        nl_list_for_each_entry(nh_a, &a->rt_nexthops,
                                               rtnh_list) {
                                if (!rtnl_route_nh_compare(nh_a, nh_b,
                                                        nh_b->ce_mask, 1)) {
                                        found = 1;
                                        break;
                                }
                        }

                        if (!found)
                                goto nh_mismatch;
                }

                for (i = 0; i < RTAX_MAX - 1; i++) {
                        if (a->rt_metrics_mask & (1 << i) &&
                            (!(b->rt_metrics_mask & (1 << i)) ||
                             a->rt_metrics[i] != b->rt_metrics[i]))
                                ROUTE_DIFF(METRICS, 1);
                }

                diff |= ROUTE_DIFF(FLAGS,
                          (a->rt_flags ^ b->rt_flags) & b->rt_flag_mask);
        } else {
                if (a->rt_nr_nh != a->rt_nr_nh)
                        goto nh_mismatch;

                /* search for a dup in each nh of a */
                nl_list_for_each_entry(nh_a, &a->rt_nexthops, rtnh_list) {
                        found = 0;
                        nl_list_for_each_entry(nh_b, &b->rt_nexthops,
                                               rtnh_list) {
                                if (!rtnl_route_nh_compare(nh_a, nh_b, ~0, 0))
                                        found = 1;
                                        break;
                        }
                        if (!found)
                                goto nh_mismatch;
                }

                /* search for a dup in each nh of b, covers case where a has
                 * dupes itself */
                nl_list_for_each_entry(nh_b, &b->rt_nexthops, rtnh_list) {
                        found = 0;
                        nl_list_for_each_entry(nh_a, &a->rt_nexthops,
                                               rtnh_list) {
                                if (!rtnl_route_nh_compare(nh_a, nh_b, ~0, 0))
                                        found = 1;
                                        break;
                        }
                        if (!found)
                                goto nh_mismatch;
                }

                for (i = 0; i < RTAX_MAX - 1; i++) {
                        if ((a->rt_metrics_mask & (1 << i)) ^
                            (b->rt_metrics_mask & (1 << i)))
                                diff |= ROUTE_DIFF(METRICS, 1);
                        else
                                diff |= ROUTE_DIFF(METRICS,
                                        a->rt_metrics[i] != b->rt_metrics[i]);
                }

                diff |= ROUTE_DIFF(FLAGS, a->rt_flags != b->rt_flags);
        }

out:
        return diff;

nh_mismatch:
        diff |= ROUTE_DIFF(MULTIPATH, 1);
        goto out;

#undef ROUTE_DIFF
}

static struct trans_tbl route_attrs[] = {
        __ADD(ROUTE_ATTR_FAMILY, family)
        __ADD(ROUTE_ATTR_TOS, tos)
        __ADD(ROUTE_ATTR_TABLE, table)
        __ADD(ROUTE_ATTR_PROTOCOL, protocol)
        __ADD(ROUTE_ATTR_SCOPE, scope)
        __ADD(ROUTE_ATTR_TYPE, type)
        __ADD(ROUTE_ATTR_FLAGS, flags)
        __ADD(ROUTE_ATTR_DST, dst)
        __ADD(ROUTE_ATTR_SRC, src)
        __ADD(ROUTE_ATTR_IIF, iif)
        __ADD(ROUTE_ATTR_OIF, oif)
        __ADD(ROUTE_ATTR_GATEWAY, gateway)
        __ADD(ROUTE_ATTR_PRIO, prio)
        __ADD(ROUTE_ATTR_PREF_SRC, pref_src)
        __ADD(ROUTE_ATTR_METRICS, metrics)
        __ADD(ROUTE_ATTR_MULTIPATH, multipath)
        __ADD(ROUTE_ATTR_REALMS, realms)
        __ADD(ROUTE_ATTR_CACHEINFO, cacheinfo)
};

static char *route_attrs2str(int attrs, char *buf, size_t len)
{
        return __flags2str(attrs, buf, len, route_attrs,
                           ARRAY_SIZE(route_attrs));
}

/**
 * @name Allocation/Freeing
 * @{
 */

struct rtnl_route *rtnl_route_alloc(void)
{
        return (struct rtnl_route *) nl_object_alloc(&route_obj_ops);
}

void rtnl_route_get(struct rtnl_route *route)
{
        nl_object_get((struct nl_object *) route);
}

void rtnl_route_put(struct rtnl_route *route)
{
        nl_object_put((struct nl_object *) route);
}

/** @} */

/**
 * @name Attributes
 * @{
 */

void rtnl_route_set_table(struct rtnl_route *route, uint32_t table)
{
        route->rt_table = table;
        route->ce_mask |= ROUTE_ATTR_TABLE;
}

uint32_t rtnl_route_get_table(struct rtnl_route *route)
{
        return route->rt_table;
}

void rtnl_route_set_scope(struct rtnl_route *route, uint8_t scope)
{
        route->rt_scope = scope;
        route->ce_mask |= ROUTE_ATTR_SCOPE;
}

uint8_t rtnl_route_get_scope(struct rtnl_route *route)
{
        return route->rt_scope;
}

void rtnl_route_set_tos(struct rtnl_route *route, uint8_t tos)
{
        route->rt_tos = tos;
        route->ce_mask |= ROUTE_ATTR_TOS;
}

uint8_t rtnl_route_get_tos(struct rtnl_route *route)
{
        return route->rt_tos;
}

void rtnl_route_set_protocol(struct rtnl_route *route, uint8_t protocol)
{
        route->rt_protocol = protocol;
        route->ce_mask |= ROUTE_ATTR_PROTOCOL;
}

uint8_t rtnl_route_get_protocol(struct rtnl_route *route)
{
        return route->rt_protocol;
}

void rtnl_route_set_priority(struct rtnl_route *route, uint32_t prio)
{
        route->rt_prio = prio;
        route->ce_mask |= ROUTE_ATTR_PRIO;
}

uint32_t rtnl_route_get_priority(struct rtnl_route *route)
{
        return route->rt_prio;
}

int rtnl_route_set_family(struct rtnl_route *route, uint8_t family)
{
        if (family != AF_INET && family != AF_INET6 && family != AF_DECnet)
                return -NLE_AF_NOSUPPORT;

        route->rt_family = family;
        route->ce_mask |= ROUTE_ATTR_FAMILY;

        return 0;
}

uint8_t rtnl_route_get_family(struct rtnl_route *route)
{
        return route->rt_family;
}

int rtnl_route_set_dst(struct rtnl_route *route, struct nl_addr *addr)
{
        if (route->ce_mask & ROUTE_ATTR_FAMILY) {
                if (addr->a_family != route->rt_family)
                        return -NLE_AF_MISMATCH;
        } else
                route->rt_family = addr->a_family;

        if (route->rt_dst)
                nl_addr_put(route->rt_dst);

        nl_addr_get(addr);
        route->rt_dst = addr;
        
        route->ce_mask |= (ROUTE_ATTR_DST | ROUTE_ATTR_FAMILY);

        return 0;
}

struct nl_addr *rtnl_route_get_dst(struct rtnl_route *route)
{
        return route->rt_dst;
}

int rtnl_route_set_src(struct rtnl_route *route, struct nl_addr *addr)
{
        if (addr->a_family == AF_INET)
                return -NLE_SRCRT_NOSUPPORT;

        if (route->ce_mask & ROUTE_ATTR_FAMILY) {
                if (addr->a_family != route->rt_family)
                        return -NLE_AF_MISMATCH;
        } else
                route->rt_family = addr->a_family;

        if (route->rt_src)
                nl_addr_put(route->rt_src);

        nl_addr_get(addr);
        route->rt_src = addr;
        route->ce_mask |= (ROUTE_ATTR_SRC | ROUTE_ATTR_FAMILY);

        return 0;
}

struct nl_addr *rtnl_route_get_src(struct rtnl_route *route)
{
        return route->rt_src;
}

int rtnl_route_set_type(struct rtnl_route *route, uint8_t type)
{
        if (type > RTN_MAX)
                return -NLE_RANGE;

        route->rt_type = type;
        route->ce_mask |= ROUTE_ATTR_TYPE;

        return 0;
}

uint8_t rtnl_route_get_type(struct rtnl_route *route)
{
        return route->rt_type;
}

void rtnl_route_set_flags(struct rtnl_route *route, uint32_t flags)
{
        route->rt_flag_mask |= flags;
        route->rt_flags |= flags;
        route->ce_mask |= ROUTE_ATTR_FLAGS;
}

void rtnl_route_unset_flags(struct rtnl_route *route, uint32_t flags)
{
        route->rt_flag_mask |= flags;
        route->rt_flags &= ~flags;
        route->ce_mask |= ROUTE_ATTR_FLAGS;
}

uint32_t rtnl_route_get_flags(struct rtnl_route *route)
{
        return route->rt_flags;
}

int rtnl_route_set_metric(struct rtnl_route *route, int metric, uint32_t value)
{
        if (metric > RTAX_MAX || metric < 1)
                return -NLE_RANGE;

        route->rt_metrics[metric - 1] = value;

        if (!(route->rt_metrics_mask & (1 << (metric - 1)))) {
                route->rt_nmetrics++;
                route->rt_metrics_mask |= (1 << (metric - 1));
        }

        route->ce_mask |= ROUTE_ATTR_METRICS;

        return 0;
}

int rtnl_route_unset_metric(struct rtnl_route *route, int metric)
{
        if (metric > RTAX_MAX || metric < 1)
                return -NLE_RANGE;

        if (route->rt_metrics_mask & (1 << (metric - 1))) {
                route->rt_nmetrics--;
                route->rt_metrics_mask &= ~(1 << (metric - 1));
        }

        return 0;
}

int rtnl_route_get_metric(struct rtnl_route *route, int metric, uint32_t *value)
{
        if (metric > RTAX_MAX || metric < 1)
                return -NLE_RANGE;

        if (!(route->rt_metrics_mask & (1 << (metric - 1))))
                return -NLE_OBJ_NOTFOUND;

        if (value)
                *value = route->rt_metrics[metric - 1];

        return 0;
}

int rtnl_route_set_pref_src(struct rtnl_route *route, struct nl_addr *addr)
{
        if (route->ce_mask & ROUTE_ATTR_FAMILY) {
                if (addr->a_family != route->rt_family)
                        return -NLE_AF_MISMATCH;
        } else
                route->rt_family = addr->a_family;

        if (route->rt_pref_src)
                nl_addr_put(route->rt_pref_src);

        nl_addr_get(addr);
        route->rt_pref_src = addr;
        route->ce_mask |= (ROUTE_ATTR_PREF_SRC | ROUTE_ATTR_FAMILY);

        return 0;
}

struct nl_addr *rtnl_route_get_pref_src(struct rtnl_route *route)
{
        return route->rt_pref_src;
}

void rtnl_route_set_iif(struct rtnl_route *route, int ifindex)
{
        route->rt_iif = ifindex;
        route->ce_mask |= ROUTE_ATTR_IIF;
}

int rtnl_route_get_iif(struct rtnl_route *route)
{
        return route->rt_iif;
}

void rtnl_route_add_nexthop(struct rtnl_route *route, struct rtnl_nexthop *nh)
{
        nl_list_add_tail(&nh->rtnh_list, &route->rt_nexthops);
        route->rt_nr_nh++;
        route->ce_mask |= ROUTE_ATTR_MULTIPATH;
}

void rtnl_route_remove_nexthop(struct rtnl_route *route, struct rtnl_nexthop *nh)
{
        route->rt_nr_nh--;
        nl_list_del(&nh->rtnh_list);
}

struct nl_list_head *rtnl_route_get_nexthops(struct rtnl_route *route)
{
        return &route->rt_nexthops;
}

int rtnl_route_get_nnexthops(struct rtnl_route *route)
{
        return route->rt_nr_nh;
}

void rtnl_route_foreach_nexthop(struct rtnl_route *r,
                                void (*cb)(struct rtnl_nexthop *, void *),
                                void *arg)
{
        struct rtnl_nexthop *nh;
    
        if (r->ce_mask & ROUTE_ATTR_MULTIPATH) {
                nl_list_for_each_entry(nh, &r->rt_nexthops, rtnh_list) {
                        cb(nh, arg);
                }
        }
}

struct rtnl_nexthop *rtnl_route_nexthop_n(struct rtnl_route *r, int n)
{
        struct rtnl_nexthop *nh;
        int i;
    
        if (r->ce_mask & ROUTE_ATTR_MULTIPATH && r->rt_nr_nh > n) {
                i = 0;
                nl_list_for_each_entry(nh, &r->rt_nexthops, rtnh_list) {
                        if (i == n) return nh;
                        i++;
                }
        }
        return NULL;
}

/** @} */

/**
 * @name Utilities
 * @{
 */

/**
 * Guess scope of a route object.
 * @arg route           Route object.
 *
 * Guesses the scope of a route object, based on the following rules:
 * @code
 *   1) Local route -> local scope
 *   2) At least one nexthop not directly connected -> universe scope
 *   3) All others -> link scope
 * @endcode
 *
 * @return Scope value.
 */
int rtnl_route_guess_scope(struct rtnl_route *route)
{
        if (route->rt_type == RTN_LOCAL)
                return RT_SCOPE_HOST;

        if (!nl_list_empty(&route->rt_nexthops)) {
                struct rtnl_nexthop *nh;

                /*
                 * Use scope uiniverse if there is at least one nexthop which
                 * is not directly connected
                 */
                nl_list_for_each_entry(nh, &route->rt_nexthops, rtnh_list) {
                        if (nh->rtnh_gateway)
                                return RT_SCOPE_UNIVERSE;
                }
        }

        return RT_SCOPE_LINK;
}

/** @} */

static struct nla_policy route_policy[RTA_MAX+1] = {
        [RTA_IIF]       = { .type = NLA_U32 },
        [RTA_OIF]       = { .type = NLA_U32 },
        [RTA_PRIORITY]  = { .type = NLA_U32 },
        [RTA_FLOW]      = { .type = NLA_U32 },
        [RTA_CACHEINFO] = { .minlen = sizeof(struct rta_cacheinfo) },
        [RTA_METRICS]   = { .type = NLA_NESTED },
        [RTA_MULTIPATH] = { .type = NLA_NESTED },
};

static int parse_multipath(struct rtnl_route *route, struct nlattr *attr)
{
        struct rtnl_nexthop *nh = NULL;
        struct rtnexthop *rtnh = nla_data(attr);
        size_t tlen = nla_len(attr);
        int err;

        while (tlen >= sizeof(*rtnh) && tlen >= rtnh->rtnh_len) {
                nh = rtnl_route_nh_alloc();
                if (!nh)
                        return -NLE_NOMEM;

                rtnl_route_nh_set_weight(nh, rtnh->rtnh_hops);
                rtnl_route_nh_set_ifindex(nh, rtnh->rtnh_ifindex);
                rtnl_route_nh_set_flags(nh, rtnh->rtnh_flags);

                if (rtnh->rtnh_len > sizeof(*rtnh)) {
                        struct nlattr *ntb[RTA_MAX + 1];

                        err = nla_parse(ntb, RTA_MAX, (struct nlattr *)
                                        RTNH_DATA(rtnh),
                                        rtnh->rtnh_len - sizeof(*rtnh),
                                        route_policy);
                        if (err < 0)
                                goto errout;

                        if (ntb[RTA_GATEWAY]) {
                                struct nl_addr *addr;

                                addr = nl_addr_alloc_attr(ntb[RTA_GATEWAY],
                                                          route->rt_family);
                                if (!addr) {
                                        err = -NLE_NOMEM;
                                        goto errout;
                                }

                                rtnl_route_nh_set_gateway(nh, addr);
                                nl_addr_put(addr);
                        }

                        if (ntb[RTA_FLOW]) {
                                uint32_t realms;
                                
                                realms = nla_get_u32(ntb[RTA_FLOW]);
                                rtnl_route_nh_set_realms(nh, realms);
                        }
                }

                rtnl_route_add_nexthop(route, nh);
                tlen -= RTNH_ALIGN(rtnh->rtnh_len);
                rtnh = RTNH_NEXT(rtnh);
        }

        err = 0;
errout:
        if (err && nh)
                rtnl_route_nh_free(nh);

        return err;
}

int rtnl_route_parse(struct nlmsghdr *nlh, struct rtnl_route **result)
{
        struct rtmsg *rtm;
        struct rtnl_route *route;
        struct nlattr *tb[RTA_MAX + 1];
        struct nl_addr *src = NULL, *dst = NULL, *addr;
        struct rtnl_nexthop *old_nh = NULL;
        int err, family;

        route = rtnl_route_alloc();
        if (!route) {
                err = -NLE_NOMEM;
                goto errout;
        }

        route->ce_msgtype = nlh->nlmsg_type;

        err = nlmsg_parse(nlh, sizeof(struct rtmsg), tb, RTA_MAX, route_policy);
        if (err < 0)
                goto errout;

        rtm = nlmsg_data(nlh);
        route->rt_family = family = rtm->rtm_family;
        route->rt_tos = rtm->rtm_tos;
        route->rt_table = rtm->rtm_table;
        route->rt_type = rtm->rtm_type;
        route->rt_scope = rtm->rtm_scope;
        route->rt_protocol = rtm->rtm_protocol;
        route->rt_flags = rtm->rtm_flags;

        route->ce_mask |= ROUTE_ATTR_FAMILY | ROUTE_ATTR_TOS |
                          ROUTE_ATTR_TABLE | ROUTE_ATTR_TYPE |
                          ROUTE_ATTR_SCOPE | ROUTE_ATTR_PROTOCOL |
                          ROUTE_ATTR_FLAGS;

        if (tb[RTA_DST]) {
                if (!(dst = nl_addr_alloc_attr(tb[RTA_DST], family)))
                        goto errout_nomem;
        } else {
                if (!(dst = nl_addr_alloc(0)))
                        goto errout_nomem;
                nl_addr_set_family(dst, rtm->rtm_family);
        }

        nl_addr_set_prefixlen(dst, rtm->rtm_dst_len);
        err = rtnl_route_set_dst(route, dst);
        if (err < 0)
                goto errout;

        nl_addr_put(dst);

        if (tb[RTA_SRC]) {
                if (!(src = nl_addr_alloc_attr(tb[RTA_SRC], family)))
                        goto errout_nomem;
        } else if (rtm->rtm_src_len)
                if (!(src = nl_addr_alloc(0)))
                        goto errout_nomem;

        if (src) {
                nl_addr_set_prefixlen(src, rtm->rtm_src_len);
                rtnl_route_set_src(route, src);
                nl_addr_put(src);
        }

        if (tb[RTA_IIF])
                rtnl_route_set_iif(route, nla_get_u32(tb[RTA_IIF]));

        if (tb[RTA_PRIORITY])
                rtnl_route_set_priority(route, nla_get_u32(tb[RTA_PRIORITY]));

        if (tb[RTA_PREFSRC]) {
                if (!(addr = nl_addr_alloc_attr(tb[RTA_PREFSRC], family)))
                        goto errout_nomem;
                rtnl_route_set_pref_src(route, addr);
                nl_addr_put(addr);
        }

        if (tb[RTA_METRICS]) {
                struct nlattr *mtb[RTAX_MAX + 1];
                int i;

                err = nla_parse_nested(mtb, RTAX_MAX, tb[RTA_METRICS], NULL);
                if (err < 0)
                        goto errout;

                for (i = 1; i <= RTAX_MAX; i++) {
                        if (mtb[i] && nla_len(mtb[i]) >= sizeof(uint32_t)) {
                                uint32_t m = nla_get_u32(mtb[i]);
                                if (rtnl_route_set_metric(route, i, m) < 0)
                                        goto errout;
                        }
                }
        }

        if (tb[RTA_MULTIPATH])
                if ((err = parse_multipath(route, tb[RTA_MULTIPATH])) < 0)
                        goto errout;

        if (tb[RTA_CACHEINFO]) {
                nla_memcpy(&route->rt_cacheinfo, tb[RTA_CACHEINFO],
                           sizeof(route->rt_cacheinfo));
                route->ce_mask |= ROUTE_ATTR_CACHEINFO;
        }

        if (tb[RTA_OIF]) {
                if (!old_nh && !(old_nh = rtnl_route_nh_alloc()))
                        goto errout;

                rtnl_route_nh_set_ifindex(old_nh, nla_get_u32(tb[RTA_OIF]));
        }

        if (tb[RTA_GATEWAY]) {
                if (!old_nh && !(old_nh = rtnl_route_nh_alloc()))
                        goto errout;

                if (!(addr = nl_addr_alloc_attr(tb[RTA_GATEWAY], family)))
                        goto errout_nomem;

                rtnl_route_nh_set_gateway(old_nh, addr);
                nl_addr_put(addr);
        }

        if (tb[RTA_FLOW]) {
                if (!old_nh && !(old_nh = rtnl_route_nh_alloc()))
                        goto errout;

                rtnl_route_nh_set_realms(old_nh, nla_get_u32(tb[RTA_FLOW]));
        }

        if (old_nh) {
                if (route->rt_nr_nh == 0) {
                        /* If no nexthops have been provided via RTA_MULTIPATH
                         * we add it as regular nexthop to maintain backwards
                         * compatibility */
                        rtnl_route_add_nexthop(route, old_nh);
                } else {
                        /* Kernel supports new style nexthop configuration,
                         * verify that it is a duplicate and discard nexthop. */
                        struct rtnl_nexthop *first;

                        first = nl_list_first_entry(&route->rt_nexthops,
                                                    struct rtnl_nexthop,
                                                    rtnh_list);
                        if (!first)
                                BUG();

                        if (rtnl_route_nh_compare(old_nh, first,
                                                  old_nh->ce_mask, 0)) {
                                err = -NLE_INVAL;
                                goto errout;
                        }

                        rtnl_route_nh_free(old_nh);
                }
        }

        *result = route;
        return 0;

errout:
        rtnl_route_put(route);
        return err;

errout_nomem:
        err = -NLE_NOMEM;
        goto errout;
}

int rtnl_route_build_msg(struct nl_msg *msg, struct rtnl_route *route)
{
        int i;
        struct nlattr *metrics;
        struct rtmsg rtmsg = {
                .rtm_family = route->rt_family,
                .rtm_tos = route->rt_tos,
                .rtm_table = route->rt_table,
                .rtm_protocol = route->rt_protocol,
                .rtm_scope = route->rt_scope,
                .rtm_type = route->rt_type,
                .rtm_flags = route->rt_flags,
        };

        if (route->rt_dst == NULL)
                return -NLE_MISSING_ATTR;

        rtmsg.rtm_dst_len = nl_addr_get_prefixlen(route->rt_dst);
        if (route->rt_src)
                rtmsg.rtm_src_len = nl_addr_get_prefixlen(route->rt_src);


        if (rtmsg.rtm_scope == RT_SCOPE_NOWHERE)
                rtmsg.rtm_scope = rtnl_route_guess_scope(route);

        if (nlmsg_append(msg, &rtmsg, sizeof(rtmsg), NLMSG_ALIGNTO) < 0)
                goto nla_put_failure;

        /* Additional table attribute replacing the 8bit in the header, was
         * required to allow more than 256 tables. */
        NLA_PUT_U32(msg, RTA_TABLE, route->rt_table);

        if (nl_addr_get_len(route->rt_dst))
                NLA_PUT_ADDR(msg, RTA_DST, route->rt_dst);
        NLA_PUT_U32(msg, RTA_PRIORITY, route->rt_prio);

        if (route->ce_mask & ROUTE_ATTR_SRC)
                NLA_PUT_ADDR(msg, RTA_SRC, route->rt_src);

        if (route->ce_mask & ROUTE_ATTR_PREF_SRC)
                NLA_PUT_ADDR(msg, RTA_PREFSRC, route->rt_pref_src);

        if (route->ce_mask & ROUTE_ATTR_IIF)
                NLA_PUT_U32(msg, RTA_IIF, route->rt_iif);

        if (route->rt_nmetrics > 0) {
                uint32_t val;

                metrics = nla_nest_start(msg, RTA_METRICS);
                if (metrics == NULL)
                        goto nla_put_failure;

                for (i = 1; i <= RTAX_MAX; i++) {
                        if (!rtnl_route_get_metric(route, i, &val))
                                NLA_PUT_U32(msg, i, val);
                }

                nla_nest_end(msg, metrics);
        }

        if (rtnl_route_get_nnexthops(route) > 0) {
                struct nlattr *multipath;
                struct rtnl_nexthop *nh;

                if (!(multipath = nla_nest_start(msg, RTA_MULTIPATH)))
                        goto nla_put_failure;

                nl_list_for_each_entry(nh, &route->rt_nexthops, rtnh_list) {
                        struct rtnexthop *rtnh;

                        rtnh = nlmsg_reserve(msg, sizeof(*rtnh), NLMSG_ALIGNTO);
                        if (!rtnh)
                                goto nla_put_failure;

                        rtnh->rtnh_flags = nh->rtnh_flags;
                        rtnh->rtnh_hops = nh->rtnh_weight;
                        rtnh->rtnh_ifindex = nh->rtnh_ifindex;

                        if (nh->rtnh_gateway)
                                NLA_PUT_ADDR(msg, RTA_GATEWAY,
                                             nh->rtnh_gateway);

                        if (nh->rtnh_realms)
                                NLA_PUT_U32(msg, RTA_FLOW, nh->rtnh_realms);

                        rtnh->rtnh_len = nlmsg_tail(msg->nm_nlh) -
                                                (void *) rtnh;
                }

                nla_nest_end(msg, multipath);
        }

        return 0;

nla_put_failure:
        return -NLE_MSGSIZE;
}

/** @cond SKIP */
struct nl_object_ops route_obj_ops = {
        .oo_name                = "route/route",
        .oo_size                = sizeof(struct rtnl_route),
        .oo_constructor         = route_constructor,
        .oo_free_data           = route_free_data,
        .oo_clone               = route_clone,
        .oo_dump = {
            [NL_DUMP_LINE]      = route_dump_line,
            [NL_DUMP_DETAILS]   = route_dump_details,
            [NL_DUMP_STATS]     = route_dump_stats,
            [NL_DUMP_ENV]       = route_dump_env,
        },
        .oo_compare             = route_compare,
        .oo_attrs2str           = route_attrs2str,
        .oo_id_attrs            = (ROUTE_ATTR_FAMILY | ROUTE_ATTR_TOS |
                                   ROUTE_ATTR_TABLE | ROUTE_ATTR_DST),
};
/** @endcond */

/** @} */